Structure of mRNA and tRNA

mRNA

• Messenger RNA is a type of RNA synthesised during transcription

• Its role is to carry genetic information from the DNA to the ribosomes (where proteins are made)

• Features of mRNA

  • Single-stranded, linear molecule

  • Contains a base sequence complementary to a DNA sequence

  • Contains codons, which are sets of three bases that code for an amino acid

  • Small enough to leave the nucleus

tRNA

• Transfer RNA is a type of RNA used in translation

• Its role is to transport amino acids to ribosomes to build up a polypeptide chain

• Features of tRNA

  • Single stranded molecule folded into a clover-leaf shape

  • Uses hydrogen bond between complementary base pairs to hold it in shape

  • Contains specific sequence of three bases at one end, known as the anticodon

  • Contains an amino acid binding site at the opposite end

Comparing mRNA and tRNA